<?php

/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Feed
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Abstract.php 18951 2009-11-12 16:26:19Z alexander $
 */


/**
 * @see Zend_Feed_Element
 */
require_once 'Zend/Feed/Element.php';


/**
 * The Zend_Feed_Abstract class is an abstract class representing feeds.
 *
 * Zend_Feed_Abstract implements two core PHP 5 interfaces: ArrayAccess and
 * Iterator. In both cases the collection being treated as an array is
 * considered to be the entry collection, such that iterating over the
 * feed takes you through each of the feed.s entries.
 *
 * @category   Zend
 * @package    Zend_Feed
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
abstract class Zend_Feed_Abstract extends Zend_Feed_Element implements Iterator, Countable
{
	/**
	 * Current index on the collection of feed entries for the
	 * Iterator implementation.
	 *
	 * @var integer
	 */
	protected $_entryIndex = 0;

	/**
	 * Cache of feed entries.
	 *
	 * @var array
	 */
	protected $_entries;

	/**
	 * Feed constructor
	 *
	 * The Zend_Feed_Abstract constructor takes the URI of a feed or a
	 * feed represented as a string and loads it as XML.
	 *
	 * @param  string $uri The full URI of the feed to load, or NULL if not retrieved via HTTP or as an array.
	 * @param  string $string The feed as a string, or NULL if retrieved via HTTP or as an array.
	 * @param  Zend_Feed_Builder_Interface $builder The feed as a builder instance or NULL if retrieved as a string or via HTTP.
	 * @return void
	 * @throws Zend_Feed_Exception If loading the feed failed.
	 */
	public function __construct($uri = null, $string = null, Zend_Feed_Builder_Interface $builder = null)
	{
		if ($uri !== null) {
			// Retrieve the feed via HTTP
			$client = Zend_Feed::getHttpClient();
			$client->setUri($uri);
			$response = $client->request('GET');
			if ($response->getStatus() !== 200) {
				/**
				 * @see Zend_Feed_Exception
				 */
				require_once 'Zend/Feed/Exception.php';
				throw new Zend_Feed_Exception('Feed failed to load, got response code ' . $response->getStatus());
			}
			$this->_element = $response->getBody();
			$this->__wakeup();
		} elseif ($string !== null) {
			// Retrieve the feed from $string
			$this->_element = $string;
			$this->__wakeup();
		} else {
			// Generate the feed from the array
			$header = $builder->getHeader();
			$this->_element = new DOMDocument('1.0', $header['charset']);
			$root = $this->_mapFeedHeaders($header);
			$this->_mapFeedEntries($root, $builder->getEntries());
			$this->_element = $root;
			$this->_buildEntryCache();
		}
	}


	/**
	 * Load the feed as an XML DOMDocument object
	 *
	 * @return void
	 * @throws Zend_Feed_Exception
	 */
	public function __wakeup()
	{
		@ini_set('track_errors', 1);
		$doc = new DOMDocument;
		$status = @$doc->loadXML($this->_element);
		@ini_restore('track_errors');

		if (!$status) {
			// prevent the class to generate an undefined variable notice (ZF-2590)
			if (!isset($php_errormsg)) {
				if (function_exists('xdebug_is_enabled')) {
					$php_errormsg = '(error message not available, when XDebug is running)';
				} else {
					$php_errormsg = '(error message not available)';
				}
			}

			/**
			 * @see Zend_Feed_Exception
			 */
			require_once 'Zend/Feed/Exception.php';
			throw new Zend_Feed_Exception("DOMDocument cannot parse XML: $php_errormsg");
		}

		$this->_element = $doc;
	}


	/**
	 * Prepare for serialiation
	 *
	 * @return array
	 */
	public function __sleep()
	{
		$this->_element = $this->saveXML();

		return array('_element');
	}


	/**
	 * Cache the individual feed elements so they don't need to be
	 * searched for on every operation.
	 *
	 * @return void
	 */
	protected function _buildEntryCache()
	{
		$this->_entries = array();
		foreach ($this->_element->childNodes as $child) {
			if ($child->localName == $this->_entryElementName) {
				$this->_entries[] = $child;
			}
		}
	}


	/**
	 * Get the number of entries in this feed object.
	 *
	 * @return integer Entry count.
	 */
	public function count()
	{
		return count($this->_entries);
	}


	/**
	 * Required by the Iterator interface.
	 *
	 * @return void
	 */
	public function rewind()
	{
		$this->_entryIndex = 0;
	}


	/**
	 * Required by the Iterator interface.
	 *
	 * @return mixed The current row, or null if no rows.
	 */
	public function current()
	{
		return new $this->_entryClassName(
		null,
		$this->_entries[$this->_entryIndex]);
	}


	/**
	 * Required by the Iterator interface.
	 *
	 * @return mixed The current row number (starts at 0), or NULL if no rows
	 */
	public function key()
	{
		return $this->_entryIndex;
	}


	/**
	 * Required by the Iterator interface.
	 *
	 * @return mixed The next row, or null if no more rows.
	 */
	public function next()
	{
		++$this->_entryIndex;
	}


	/**
	 * Required by the Iterator interface.
	 *
	 * @return boolean Whether the iteration is valid
	 */
	public function valid()
	{
		return 0 <= $this->_entryIndex && $this->_entryIndex < $this->count();
	}

	/**
	 * Generate the header of the feed when working in write mode
	 *
	 * @param  array $array the data to use
	 * @return DOMElement root node
	 */
	abstract protected function _mapFeedHeaders($array);

	/**
	 * Generate the entries of the feed when working in write mode
	 *
	 * @param  DOMElement $root the root node to use
	 * @param  array $array the data to use
	 * @return DOMElement root node
	 */
	abstract protected function _mapFeedEntries(DOMElement $root, $array);

	/**
	 * Send feed to a http client with the correct header
	 *
	 * @throws Zend_Feed_Exception if headers have already been sent
	 * @return void
	 */
	abstract public function send();
}
